Navigation is broadly defined as the process of assisting movement between a starting position and a destination. Navigation includes the movement of vehicles (e.g., land-based, air-based, and water-based vehicles) and pedestrians. Early navigation relied on the stars (e.g., the North Star) and other natural landmarks. Even today, people may use natural and/or man-made landmarks to navigate (e.g., “go toward the mountains” or “go past the gas station on your left”). Instruments (e.g., the compass) have long been used to assist in navigation. More recently, the development of global positioning system (GPS) devices, and even map applications available on most newer mobile devices (e.g., smart phones and tablets), have made it easier to navigate.